Older Merc 165 hard to start after a hard run, runs rough, dies

[achris]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

???

Just be patient, I can't be awake 25 hours a day, and I do live on the other side of the planet!

How hard is a carb rebuild by the way ? I don't mind rebuilding one if it can be done by a somewhat-capable person.

Yes. Have you ever done a carbie before? Just follow the manual step by step. Don't miss anything out and don't jump ahead. When the setting says 3/8", it means 3/8", not a 1/4" or 1/2", but 3/8". Use DRY compressed air and a can (or 3) of carbie cleaner. Get a full repair kit for the carbie and if you have ANY doubts, head back here...

Also read it might be the low-pressure fuel pump leaking fuel internally. Could this also cause the rough start/idle when warm as the engine could be flooded while it's off ???

If the pump was leaking you would have fuel in the clear yellow hose up to the carbie and the engine would stall, especially as you opened the throttle.... Assuming your ignition system is in good shape, the carbie rebuild should sort it out...

Chris.....

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Just be patient, I can't be awake 25 hours a day, and I do live on the other side of the planet!

No worries mate ! I accidently posted two posts and had to edit one out. Replaced it with ???'s :redface:

Also, I have rebuilt 4-in-1 carbs on my motorcycle a couple times, but had very good step by step directions. Manual #2 from Mercruiser is a bit more complex with its steps.

Also, what should be in the clear, yellow hose ? I suppose fuel mist instead of liquid fuel ? Would it do this all the time or when the motor is running only ? Thanks again.

 

[achris]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

The clear yellow hose should be empty. If the diaphragm in the fuel pump ruptures, then instead of the fuel going into the sump, it goes up the tube and into the carbie throat, choking the engine and stopping the pump....

 

[glastronomic]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

I have the very same engine and replaced the mechanical fuel pump with an electrical one.
One thing to check is the ignition rotor shaft for slop in the bearing, makes it run erratic.
Plus points and timing
Good idea to change gear oil and impeller in leg, and check thermostat/water pump on engine for being in good working order and check all the other items like fuel hoses, leads etc.etc.
Archis is the MAN with the knowledge!

fuel pump and glass bowl underneath

inline fuelfilter rigged up with 2 fueltanks and electric fuel pump
Good luck

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

I have the very same engine and replaced the mechanical fuel pump with an electrical one.
One thing to check is the ignition rotor shaft for slop in the bearing, makes it run erratic.
Plus points and timing
Good idea to change gear oil and impeller in leg, and check thermostat/water pump on engine for being in good working order and check all the other items like fuel hoses, leads etc.etc.

Although ignition might be the problem, I am leaning towards a fuel problem. The motor starts like a charm when cold and once started hot, has no problems with misfires, etc. From 5 hours of researching, came to the conclusion it might be vapor lock in the fuel system. That or the carb will have to be re-done (which I'm planning on doing either way). I found some "fuel line cooler kits" and wondering if I should give that a go. That, or riggin' up my own creation to keep that fuel line cool...

 

[riptorn]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Have you taken off the breather to see if the choke was working properly on warm up? Does it open up as the motor warms up? Your heat riser tube could be broken or not adjusted right. P.O. could have been playing with the adjustment.

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Have you taken off the breather to see if the choke was working properly on warm up? Does it open up as the motor warms up? Your heat riser tube could be broken or not adjusted right. P.O. could have been playing with the adjustment.

Thanks for the tip ! I'm on the road next couple of days but will definitely check out the choke operation. Is there specific info on how much it opens at a specific temp or just have to eyeball it ?

Also, are there specific manuals available with step by step directions for a Rochester 2GC carb rebuild ? I think the SELOC manual has info about this from section 4-27 thru 4-33 from what I could see in the table of contents preview, but not being able to see actual photos, I don't know if it's clear enough.

 

[riptorn]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Have look to see it the previous own had adjusted it. Should be marks where the screw clips were. You just have to make sure the flap is open all the way when the motor warms up. Your heat tube could be plugged or broken. I played with the adjustment on my choke and ended up putting it back the way it was.
I have a carb in my garage I forgot to give the buyer. I'll have a look. Shouldn't be too difficult to rebuild a 2 brl. Might not have to if it is a choke problem.
Also, do you have a backup coil?

 

[ShowMeGuy]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

OOPS! I looked at his serial number and posted (what I thought) was manual #2..... (Obviously I clicked the wrong link :facepalm

try this -> https://docs.google.com/open?id=0B1TAvwZ3TjhfOTI5OTMyZTMtNDNkZi00MDAyLWE5MTYtMTI5N2MyNDM3NjZm

Chris......
Good catch Ziggy, thanks... :redface:

You kind sir wouldn't happen to have a linke to teh Manual #1 to download would ya?

 

[achris]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

You kind sir wouldn't happen to have a linke to teh Manual #1 to download would ya?

https://docs.google.com/open?id=0B1TAvwZ3TjhfZTgyNWM4MjQtOTdhOS00ODEyLTk1OGEtOGIwOGYwNzAwNGEz

 

[ShowMeGuy]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

SKEW! thx

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Well, took her out a second time this weekend. Prior to putting on the water, changed the fuel filter in the bell housing of the fuel pump, cleaned up the plugs a bit and put in fresh 93 octane gas (the previous time mistakingly gassed her up with 87).. Started up fine as always when cold, took her WOT for about 10 mins to normal operating temps and shut her down, expecting the hard-start to return. To my pleasant surprise, she started right up when hot and didn't give any problems all day until evening.

After about a 20 mile cruise at about 3,000 rpm she started sputtering like she was running out of gas (she wasn't). Then all of a sudden she just died in the middle of the lake. Strange. When I went to restart her, the starter BAAAREEELLLYY turned, not even a full motor revolution, almost like the battery was dead. (It wasn't). Finally, about 5 minutes later, she started up but ONLY with the throttle about 1/2 open. As soon as I tried to put it back in idle, she died again. Again, starter barely turned the motor.

Long story short, got her back to the dock, shut her down and any attempt to start her, were only CLICK, CLICK, CLICK of the starter solenoid. Battery tested good. What gives ? Any help appreciated.

 

[achris]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Sounds like a bad connection somewhere. The poor running will have been due to low voltage to the coil producing a weak spark. Start by cleaning ALL the electrical connections between the battery posts (yes, BOTH OF THEM!) and the engine, and don't forget the negative cables too....

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

That's my little project for tomorrow then: clean EVERY terminal, nut, bolt, washer, cable, wire, connector, connection... well, you get it.

Also, someone mentioned a faulty slave solenoid, a faulty starter main solenoid or even a seized up starter. Just keeps clicking .....Might have to take that off and take it to the auto parts store for a test.

 

[riptorn]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Are you over heating? How does she start now? Is your temp gauge working? Choke must be fine?
Wish you the best

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Are you over heating? How does she start now? Is your temp gauge working? Choke must be fine?
Wish you the best

She stays between 140* - 180* depending how I run her. Never over 180* that I noticed.
She doesn't start right now. Just CLICK, CLICK, CLICK and nothing more. Prior to the clicking, it started turning REALLLLYY SLLLOOWWW after it just died in the middle of the lake. :facepalm:
Choke seems like it's 95% open when hot (has a bit more possible movement to fully vertical position).

 

[achris]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

If the battery's good and all the connections are good... Then you could have a starter motor going out... Use a DMM and check for voltage drop between each point, and don't forget those grounds...

The easiest one to start with will be the positive. I would meter between the positive post on the battery and the main motor post on the starter. While cranking you want to see less than 0.5 volts (the lower, the better), and then measure negative post to the starter motor frame... same rule, less is better... If you see more on either test, you're looking for a bad connection. If both are good, new starter motor.

Chris......

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

While cranking you want to see less than 0.5 volts (the lower, the better), and then measure negative post to the starter motor frame... same rule, less is better...

It's not cranking. Just CLICKING. I get absolutely no turn of the motor....

 

[achris]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

It's not cranking. Just CLICKING. I get absolutely no turn of the motor....

Then instead of the starter motor post, go to the output post on the solenoid... All the above still applies...

 

[riptorn]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

She stays between 140* - 180* depending how I run her. Never over 180* that I noticed.
She doesn't start right now. Just CLICK, CLICK, CLICK and nothing more. Prior to the clicking, it started turning REALLLLYY SLLLOOWWW after it just died in the middle of the lake. :facepalm:
Choke seems like it's 95% open when hot (has a bit more possible movement to fully vertical position).

Choke flap should be fully open+ when running at least 20 minutes. Now you have a starter problem. Are you reading your reply posts?